<!doctype html>
<body>
  <style>
    #area {
      border: 1px solid black; 
      width: 90%; 
      height: 180px; 
      cursor: pointer;
      overflow: scroll;
      user-select: none;
    }
  </style>
  
  <div id="area">
  Multi-touch here
  </div>
  <script>
    document.onpointerdown = document.onpointerup = log;

    function log(event) {
      area.insertAdjacentHTML("beforeend", `
        <div>${event.type} isPrimary=${event.isPrimary} pointerId=${event.pointerId}</div>
      `)
     area.scrollTop = 1e9;
    }
  </script>

</body>
